Dishwashing apparatus



4 w. R. WALKER 2,692,604

DISHWASHING APPARATUS Filed Dec, 22, 1951 2 Sheets-Sheet l 46 IN YE NTDR- WILLARD R. WALKER A T TUHNEY Oct. 26, 1954 w R WALKER 2,692,604

DISHWASHING APPARATUS Filed Dec. 22, 1951 2 Sheets-Sheet 2 SIGNAL LAM P TIMER MOTOR M OTOR DRAIN //4 WATER mus-r VALVE BY PASS VALVE COVER SOLENOID l I Emma 36 0 i //2 62 I I BY PA \mw:

INK/E NTDR WILLARD E. WALKER ATTUHNEY' Patented Oct. 26, 1954 DISHWASHIN G APPARATUS Willard E. Walker, Syracuse, N. Y., assignor to Easy Washing Machine Corporation, Syracuse, N. Y., a corporation of Delaware Application December 22, 1951, Serial No. 262,926

1 Claim. 1

This invention relates to dish washers, and more particularly to apparatus for utilizing wash water at one temperature and rinse water at an elevated temperature.

In the washing of dishes, it has generally been considered that the effectiveness of the washing operation and rapid drying of the dishes thereafter in part depend upon the temperature of the wash water used, the effectiveness increasing with temperature. The use of extremely hot water such as would be desirable for rinsing and drying, however, in conjunction with detergents and particularly the synthetic type, may be detrimental to the dishes, and particularly to any design or decoration upon the dishes, the effect becoming apparent after repeated washings. Further, utilizing high temperatures initially in washing has a tendency to cook rather than dissolve certain food deposits, causing such deposts to tenaciously adhere to the dishes, preventing a satisfactory wash through the usual splash methods generally employed in dish washing machines.

The present invention is directed to an arrangement in which washing is effected utilizing water not in excess of 140 F., and in which after the washing has been completed and the detergents eliminated, rinse water of a higher temperature is introduced.

The invention is also directed to apparatus for automatically effecting washing and rinsing, utilizing higher temperature water for the rinsing operation obtained from a small high temperature storage reservoir.

The invention is further directed to apparatus of the type described in which rinse water is stored in a small reservoir at a high temperature, and in which rinse water is withdrawn from storage and replaced by hot water from the domestic supply, the temperature of the replaced hot water being gradually increased to the high temperature desired by a thermostatically controlled heater associated with the reservoir.

The invention is further directed to a storage supply for hot water for rinsing, from which a major portion of the hot water may be withdrawn with substantially no dilution or temperature drop from incoming replacement lower temperature water.

The above and other novel features of the invention will appear more fully hereinafter from the following detailed description when taken in conjunction with the accompanying drawings. It is expressly understood that the drawings are employed for purposes of illustration only and are not designed as a definition of the limits of the invention, reference being had for this purpose to the appended claim.

In the drawings, wherein like reference characters indicate like parts:

Figure 1 is an elevational view, with parts in section, showing the general arrangement;

Figure 2 is a sectional view taken on the line 2-2 through the bypass valve;

Figure 3 is a section taken through the line 3-3 of Figure 2, through the bypass valve;

Figure 4 is a section taken on the line 4-4 of Figure 3, through the bypass valve;

Figure 5 is a time control chart; and

Figure 6 is a circuit diagram for the time control.

In Figure 1, there is shown a cabinet structure 10 having a dish washing tub I2 contained therein, the tub having a lid I l hinged at l6 and held closed by a latch mechanism [8 released by a solenoid 20. Such lid may be counterbalanced or resiliently biased to open position. Closure of the lid i4 actuates a switch 22 adapted to stop the cycle of operation of the apparatus whenever the lid is opened. The tub is provided with a suitable impeller 2t driven by a motor 26 through a belt drive 28. The tub is provided with a drain 30 with a solenoid controlled drain valve 32. A water inlet system comprises a conduit 34 adapted to be connected to a source of hot water of a domestic hot water supply system, the conduit 34 leading to a solenoid controlled master valve 36, such valve controlling the fiow of water through a supply conduit 38 having a discharge nozzle 46 directed into a tub inlet supply pocket 42. Interposed between said supply conduit 38 is a three-way or bypass valve 52 having an inlet connection 53 extending to the master control valve 36.

Located in the base of the cabinet I 0 is a storage tank or reservoir 44 surrounded by heat insulation 46, such tank being connected to the conduit 38 as at 48 by an outlet pipe 41. Such tank is fed from the master valve 36 by means of a tank inlet pipe connected to one outlet branch of the solenoid-controlled three-way.

valve 52. The other outlet branch of the three- .way valve is connected through the pipe 54 to conduit 38. Thus the three-way valve is adapted to supply water to the base of the tank or reservoir 44 through the inlet pipe 50, causing hot water from the tank to be delivered to the nozzle 40 or deliver domestic hot water direct to the nozzle 40. The tank 44 is bafiled as at 56 adjacent the inlet end, so that intermixing of inlet water with outlet water is substantially prevented, the inlet water tending to rise in the tank in a substantially level plane.

The tank is provided with a heating element 60' which is thermostatically controlled as at 62. Such heating element may be of relatively low wattage, since the requirements will be to raise the temperature of the water fed into the reservoir from the domestic hot water supply from approximately 140 to the desired rinsing temperature of 180, and to hold the water at the elevated temperature in readiness for rinsing as will be hereinafter described in detail. By reason of the thick insulation around the tank, and the baffling adjacent the inlet and outlet connections thereto, it is possible to maintain a supply of hot water within the tank at all times and to withdraw from the tank a major portion of the water contained therein for rinsing purposes without dilution by inlet water and without any appreciable temperature drop. Thus, a small quantity of water may be maintained at a suitable rinsing temperature or slowly brought to such temperature by the heater, and the major portion of such water delivered to the dish washing machine for rinsing purposes at the selected temperature.

A three-way valve 52 suitable for controlling the flow of domestic water either directly into the wash tub or to replenish the storage reservoir for hot water delivered therefrom to the wash tub, is illustrated in detail in Figures 24. Such a valve may comprise a casing 64 having a cylindrical bore 65, in which there is positioned a slide valve 56 having a thimble 68 at its lower end and a solenoid-actuated shank I at its upper end. The lower end of the casing is provided with an inlet port "I2, connected through pipe 53 to the master valve 36. The casing is provided with angularly staggered outlet ports I4 and H5, either one being adapted to be aligned with the port 18 in the thimble 88 by movement of such thimble from a lower position as shown in Figure 3 to an upper position where such port I8 will align with port It. The solenoid-actuated stem 19 is biased downwardly by a spring 88, and such shank Iii is ported lengthwise thereof as at 32 so as to minimize pressure difierences upon the slide valve and thimble. The valve member 66 may be keyed against rotation by a set screw 84 adapted to ride in a guide channel 86 formed in the casing 64.

As shown, the valve is biased to a position connecting the outflow of the master valve 36 to the reservoir Ml. The energization of the solenoid will shift the valve so as to deliver outflow from the master valve direct to the wash tube I2.

In washing dishes with the apparatus thus described, the tub is suitably loaded with dishes, and a quantity of detergent supplied; whereupon the lid is closed. In Figures and 6, the typical circuit and time diagram is disclosed for effectively utilizing the apparatus set forth. The length of the bars opposite the various control devices serves to indicate the sequence and time of energization of the various electrical devices. Upon closure of the manual switch 90, a circuit is established through line 92 to the timer motor 94, which commences rotation of the control cams, at the same time switch 96 is closed establishing a circuit through a signal lamp 98, such circuit being closed by cam-controlled contact I953 for a short interval as indicated on Figure 5 by the bar I52. The cam-actuated switch arm Ind after a brief interval closes contact I06 and opens contact I82, the timer motor 93 is energized independently of the switch 90, the signal cycles.

light 98 is de-energized, and the switch and 96 are then opened, the timer motor actuating the cams through the remainder of the cycle during the period represented by the bar I08.

Shortly thereafter, the water inlet or master valve 35 and the bypass or three-way valve 52 are simultaneously energized by closing contacts Ill] and II2 for periods indicated by the bars II and II6. Thus a quantity of wash water is admitted at domestic supply temperature, for example, F. After flow for a brief period, the drain valve and motor run contact H8 is closed for a period indicated by the bar I20. By delaying the closing of the drain valve 32 until a few seconds after wash water commences to flow into the tub, a tub pre-rinse is effected. The motor and drain valve contacts II8 are then opened after about 3 minutes, the tub drained, and then the valves 36 and 52 are again energized to introduce a second quantity of wash water at 140, as indicated by bars I22 and I 24, shortly after which the drain valve is closed and the motor started as indicated by bar I26. At the end of a two minute interval, the motor driven impeller is stopped, the drain valve 32 opened, and after a drain period, water is admitted from the booster reservoir 44 by actuation of master valve 36 only for a period represented by bar I28. Again the drain valve and motor impeller are energized during a rinsing period represented by the bar I30. Thereafter, the motor is stopped, the drain valve opened, and after a suilicient drain period, water is again admitted from the booster reservoir for a period as indicated at I32, and the motor started and the drain valve closed for a period indicated at I34.

After completion of the last rinse period, contact I38 is closed as indicated at I40 to release the lid and open the tub to permit the hot vapor to escape and permit the heated dishes to dry. An auxiliary switch for opening the lid at other times may be provided as at I36. The rate of flow of water through the master valve is preferably regulated, so that by the time periods referred to, definite quantities of water are admitted to the tub. In the first and second rinses, occurring for periods of time represented by the bars I28 and I32, approximately one gallon of water flows for each rinse, so that a three-gallon tank holds suihcient water of booster temperature to effect both rinses, and retain one gallon within the tank as a protective blanket against mixing between the inlet water and the heated water within the tank delivered through the tank outlet.

Thus a hot rinse, effective to sterilize as well as cause the dishes to dry themselves results, after effecting a wash in two stages at an efiective washing temperature. During the washing operation, the temperature within the booster tank may be restored to F., without heavy power requirements, in the event a previous wash has been completed, so that the dish washer may operate with equal effectiveness in successive As will be seen from the circuit diagram, the reservoir heater may remain in circuit constantly, and because of the insulation, little power will be consumed in maintaining the reservoir supply in readiness at the 180 level.

Although a single embodiment of the invention has been illustrated and described, it is to be understood that the invention is not limited thereto. As various changes in the construction and arrangement may be made without departing from the spirit of the invention, as will be 5 apparent to those skilled in the art, reference will be had to the appended claim for a definition of the limits of the invention.

What is claimed is:

In a dish washing apparatus, in combination, a tub having a drain valve, an inlet, and a motor driven impeller, means for supplying water to said inlet including a master valve, said means being adapted for connection to a source of domestic hot water, a storage tank, a three-way valve in said supply means between said master valve and said inlet, a connection from said threeway valve to said storage tank at the lower end thereof, a connection from said storage tank at the upper end thereof to said supply means between said three-way valve and said inlet, means within said tank to restrict water entering said tank from immediate outflow, heating means for said tank, a thermostat control for said heating means adapted to render the heating means effective when the water temperature within said 6 tank drops below an efiective rinsing temperature, said efiective rinsing temperature being above the temperature of the water from the supply means, and a timer controlling device for said drain valve, motor driven impeller, master valve and three-way valve, said device being adapted to admit a quantity of wash water to said tub solely through said supply means, subsequently open said drain valve and thereafter admit a quantity of rinse water to said tub solely from said storage tank.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,695,412 C'otterill Dec. 18, 1928 1,995,331 Snyder Mar. 26, 1935 2,2 4,2 Clark Sept. 2, 1941 2,471,506 Wiswall May 31, 194 2,561,631 Negri July 2 1951 

